The value of semen analysis and sperm function assays in predicting pregnancy among infertile couples

The role of sperm creatine kinase in the assessment of male fertility

The lack of reliable methods to assess sperm fertilizing potential has been a long-standing problem for infertile couples and for their physicians. The most widely used tests, the measurements of sperm concentrations, motility, velocity and morphology in the ejaculate, are of limited utility. Indeed, following intrauterine insemination, a treatment that compensates for low motile sperm concentrations, there were no significant differences found in semen parameters among those who did or did not achieve pregnancies. Other available assays probing for selected sperm functions, such as membrane integrity, acrosome enzyme activity, bovine cervical mucus penetration test, zona-free hamster oocyte penetration test and sperm binding to various carbohydrates,10–13 have all failed thus far to consistently predict male fertility. It became increasingly obvious that there was a need to identify cellular markers of sperm quality and fertilizing potential.

Semen characteristics: Advancement in andrological assessment

Progress in diagnosis of infertility, has been dramatically increased during the past decades with changes occurring in virtually all aspects of infertility research, thus providing innovative diagnostic testing and sophisticated instrumentation for improved management and treatment of infertility. There are about 50% of infertile couples who are suffering because of male infertility. Semen examination is a basic investigation for these infertile couples. It not only reveals the quantity and quality of sperm but also the quality of the seminal plasma, which is essential for normal sperm function. In this review, the recent advancement in investigation procedures has been analyzed which are very important in clinical practice to (a) evaluate the sperm fertilizing ability (Acrosin, aniline blue, HOS), (b) characterization of male accessory sex glands secretions (Fructose, alpha-glucosidase, PSA) and (c) the management of azoospermic patients. It is believed that use of such diagnostic procedures will facilitate wide selection of patients for whom an effective therapy might be then possible.

The management of unexplained infertility

Unexplained infertility is a diagnosis made by exclusion after all of the standard investigations have revealed no abnormality (1). The range of the prevalence is from 6 to 60 percent (23), depending on the diagnostic criteria. This article reviews the literature in the management of unexplained infertility; published data suggest no benefit of danazol or bromocriptine. The empirical use of clomiphene citrate suggests that ovarian stimulation using clomiphene citrate can double the spontaneous pregnancy rate (52, 58, 59). Induction of ovulation with human menopausal gonadotrophin (hMG) yields an overall pregnancy rate between 2 and 26 percent per cycle (68, 74). These results seem to be lower than those reported for in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT) procedures in similar patients (25-30 percent (92, 95)). Based on the literature, a rational treatment plan for treating infertility in couples with unexplained infertility includes up to four cycles of clomiphene citrate with or without intrauterine insemination (IUI). Superovulation with hMG and IUI or stimulated intrauterine insemination (SIUI) is the next step for three-cycle treatments and if unsuccessful, one of the variants of assisted reproductive techniques (ART) should be considered.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will understand the appropriate tests and work up for unexplained infertility, the various treatment options for the unexplained infertility couple including which drugs are effective and not effective, and to be able to outline an appropriate treatment plan for such patients.

Is intracytoplasmic sperm injection necessary for couples undergoing in vitro fertilization-embryo transfer with normal semen analyses but failing hamster egg penetration assays?

PURPOSE

Our purpose was to assess whether in vitro fertilization (IVF)-embryo transfer (ET) candidate couples with basically normal semen analyses but failing zona-free hamster egg penetration assay (HEPA) scores benefit from intracytoplasmic sperm injection (ICSI).

METHODS

Twenty consecutive IVF candidate couples with normal-borderline semen analyses and failing HEPA scores were recruited. Mature oocytes obtained from each woman were randomly divided between ICSI (group I; n = 126 oocytes) and standard insemination techniques (group II; 138 oocytes). Fertilization (two pronuclei) and cleavage (2-4 cells) rates were assessed for both groups.

RESULTS

There were no statistically significant differences between the two groups with respect to (mean +/- standard error of the mean) fertilization (group I, 63.1 +/- 7.75; group II, 77.8 +/- 4.7%) or cleavage (group I, 87.3 +/- 2.4%; group II, 91.2 +/- 3.5%) rates.

CONCLUSIONS

ICSI is not beneficial for IVF-ET when sperm samples demonstrate a failing HEPA score but have normal or minimally compromised semen analysis parameters.

Papanicolaou and Kruger assessment of sperm morphology: thresholds and agreement

The current World Health Organization guidelines (1992) suggest that the presence of > or = 30% normal sperm forms (i.e. PAP criteria) is consistent with normal semen quality. Critical evaluation of sperm morphology (CE; Kruger classification) has shown an excellent correlation with human in vitro fertilization. Utilizing Kruger criteria, > 14% normal sperm forms has been proposed as indicative of normal semen quality. We have performed a retrospective analysis on 261 individuals to assess the agreement between PAP and Kruger criteria for normal sperm morphology (NSM). When the threshold for NSM by PAP was set at 30%, a significant agreement was found between the percentage normal forms of both criteria (Kappa coefficient = 0.37; p < 0.001). Sixty-seven (92%) of the 73 men found to have abnormal sperm morphology by PAP had abnormal semen by Kruger classification. When the threshold for NSM by PAP was established at 50%, the Kappa coefficient was 0.48 (p < 0.001). Sixty of the 72 samples (83%) classified as normal by PAP staining were normal by Kruger criteria. Interestingly, when NSM by PAP was between 30 and 50%, the specimen was just as likely to have normal or abnormal sperm morphology by Kruger (40 vs. 60%, respectively). These results strongly suggest that a high or low percentage of NSM by PAP is in agreement with the Kruger classification. The excellent agreement of Kruger and WHO criteria at the extremes (< 30% and > 50%) may obviate the need for Kruger assessment. However, when WHO morphology is between 30 and 50%, the addition of Kruger evaluation may provide meaningful information to help better diagnose a patient and plan his treatment.

Relation between semen quality and fertility: a population-based study of 430 first-pregnancy planners

BACKGROUND

Semen analysis is part of the routine assessment of infertile couples. WHO defines a sperm concentration above 20x10(6) per mL seminal fluid as normal. We studied the association between semen quality and the probability of conception in a single menstrual cycle in Danish couples with no previous reproductive experience.

METHODS

In 1992-94, we invited 52,255 trades-union members aged 20-35 years, who lived with a partner and had no children to take part in the study; 430 couples agreed. The couples discontinued use of contraception, and were followed up for six menstrual cycles or until a pregnancy was verified within this period. Each man was asked to provide a semen sample at enrolment (which was analysed without freezing). Women kept a daily record of vaginal bleeding and sexual activity. The association between semen quality and likelihood of pregnancy was assessed by logistic regression, adjusted for sexual activity and female factors associated with low fertility.

RESULTS

There were 256 (59.5%) pregnancies among the 430 couples: 165 (65.0%) among those with a sperm concentration of 40x10(6)/mL or more and 84 (51.2%) among those with lower sperm concentrations. The probability of conception increased with increasing sperm concentration up to 40x10(6)/mL, but any higher sperm density was not associated with additional likelihood of pregnancy. The proportion of sperm with normal morphology was strongly related to likelihood of pregnancy independently of sperm concentration. Semen volume and motility were of limited value in pregnancy prediction.

INTERPRETATION

Our study suggests that the current WHO guidelines for normal semen quality should be used with caution. Some men with sperm counts above the lower limit of the normal range defined by WHO may in fact be subfertile.

Suppression of testicular and epididymal functions in a non-human primate (bonnet monkey) by combined administration of a gonadotropin-releasing hormone antagonist and testosterone buciclate

The ability of a long-acting androgen, testosterone buciclate (TB), to induce suppression of testicular and epididymal sperm functions when given in combination with a potent GnRH antagonist (Antide) either on day 1 or 45 of Antide administration (days 1-90) as well as the ability of TB to maintain Antide-induced suppression of spermatogenesis were evaluated in adult bonnet monkeys. A group of untreated animals (group I) acted as controls. All animals given Antide and androgen simultaneously (group II) became azoospermic but at different times. When androgen administration was delayed 45 days after start of Antide treatment (group III), the mean sperm concentration remained in the normospermic range and only three animals became azoospermic. Antide given alone (group IV) induced azoospermia in three animals and oligospermia in the remaining animals; spermatogenesis recovered when Antide was withdrawn and TB was injected. In all Antide-treated animals (groups II-IV), non-motile spermatozoa or sperm with non-progressive motility and poor gel penetrability were seen in the ejaculate.

A quality control system for the optimized sperm penetration assay

OBJECTIVE

To develop a quality control system for the optimized sperm penetration assay (SPA) and to use this system to monitor interassay variability and stability over time.

DESIGN

Four semen donors were tested consecutively for a period of weeks (7 to 139 weeks) with the SPA. Their average semen analyses and SPA scores were evaluated to monitor natural biologic variation. Intra-assay variation was obtained by dividing 11 semen samples into three aliquots and testing each separately in the SPA. A single ejaculate from seven individuals was aliquoted and frozen to be used as a control. They were tested on different assay days in 1986 and subsequently in 1991 to evaluate the assay stability over time.

MAIN OUTCOME MEASURES

Results were expressed as a sperm capacitation index (mean number of sperm penetrations per ovum).

RESULTS

Consecutive weekly semen analyses and SPAs on donors exhibited coefficients of variation ranging from 20% to > 40%. In contrast, these variations were much greater than intra-assay variability. Analysis of frozen semen specimens tested in several SPAs also displayed a low coefficient of variation. When aliquots of these frozen samples were tested in the SPA 5 years later, there were no differences in the observed values, showing the remarkable stability of this assay over time. The lower limit of the normal fertile range did not change over a period of 2 years.

CONCLUSIONS

Results show that using fresh semen samples as a positive control in the SPA is inadequate. This deficiency has been overcome with the use of frozen semen controls. With frozen semen for quality control, the optimized SPA developed in this laboratory is a highly reproducible assay that meets the strict criteria required for clinical laboratory certification.

Effects of testosterone buciclate on testicular and epididymal sperm functions in bonnet monkeys (Macaca radiata)

The effects of testosterone buciclate (TB), a long-acting androgen ester given i.m. at four sites (20 mg/site) on days 1 and 91 of the study period (360 days), on reproductive and hormonal parameters were evaluated in five adult male bonnet monkeys; untreated animals (n = 5) acted as controls to monitor seasonal changes in these parameters. In control animals, testicular volume remained unchanged throughout the study; sperm count, motility and gel penetrability decreased while the percentage of spermatozoa showing retention of cytoplasmic droplet and coiled tail increased in June-July (days 210-240), preceded by reduction in serum testosterone (T) levels on days 120-150 (March-April). The TB-treated animals showed reduced testicular volume (days 90-270), suppressed sperm motility and gel penetrability (days 45-240 except on day 120), decreased sperm count (days 75-270), and an increased percentage of spermatozoa showing retention of cytoplasmic droplet and coiled tail (days 45-240 except on day 120). Even though serum T levels remained elevated until day 300, these levels were within the physiological range. The changes induced by TB were reversible. The suppression of testicular and epididymal functions by TB indicates that this long-acting androgen may have the potentiality to induce and maintain reversible sterility, but further evaluation needs to be carried out to develop an appropriate dosage regimen that would prevent return to normal functions in order to develop this long-acting androgen as a hormonal male contraceptive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine triphosphate and motility characteristics of fresh and cryopreserved human spermatozoa

The concentration of ATP and the motility of human spermatozoa was measured in fresh and cryopreserved cells from the same 15 ejaculates. No coherent picture of the relationship between motility and ATP concentration emerged in whole semen or in spermatozoa washed by repeated centrifugation and resuspension in Biggers Whitten and Whittingham medium. This may have been due to the presence of dead spermatozoa and contaminating cells. After preparation on a Percoll gradient, the ATP concentration in fresh and cryopreserved spermatozoa was the same (6 +/- 0.7 nmol/10(8) spermatozoa) but 85 +/- 2.5% of the fresh spermatozoa were progressively motile with an average path velocity of 55 +/- 3.5 microns/s compared to corresponding values of 33 +/- 5.3% and 44 +/- 3.4 microns/s in frozen/thawed spermatozoa. This suggests that the poor motility of cryopreserved spermatozoa does not result from deficient ATP production. No relationship was found between ATP concentration and the ability of motile spermatozoa in the ejaculate to survive freezing.

Long-term follow-up of couples after hamster egg penetration testing

OBJECTIVE

To determine the clinical usefulness of the zona-free hamster egg penetration test as a long-term prognostic indicator for future pregnancy.

SETTING

Division of Reproductive Endocrinology and Infertility at the Washington University Medical Center.

PARTICIPANTS

All couples (n = 148) who had a hamster egg penetration assay performed between March 1, 1985 and December 31, 1986 were identified and followed with direct or telephone contact up to 68 months after the initial assay.

MAIN OUTCOME MEASURE

The monthly fecundity rates using life table analysis and the 5-year incidence of pregnancy were categorized by the percentage of hamster eggs penetrated and by history of previous urologic surgery.

RESULTS

There were no significant differences in the rate nor incidence of pregnancy in couples with hamster egg penetration scores of 0%, > 0% and < or = 10%, > 10% and < or = 20%, or > 20%. Although men with previous urologic surgery tended to have lower scores, there was no significant difference in the 5-year incidence of pregnancy.

CONCLUSION

The hamster egg penetration score is not predictive of incidence of pregnancy nor time to conception.

Incomplete development of human spermatozoa is associated with increased creatine phosphokinase concentration and abnormal head morphology

Our previous creatine phosphokinase (CK) activity studies in human sperm revealed differences among men and among sperm populations within the same specimen. Samples with low sperm concentrations, high incidence of abnormal sperm morphology, and diminished fertility had higher per sperm CK activity. In the present work, we demonstrated, with 14C-FDNB covalent CK active site modification and with direct CK immunocytochemistry, that the higher CK activity is related to an increased content of CK and of other proteins in sperm. Also, sperm heads with higher CK content were significantly larger and rounder and showed a higher incidence of amorph configuration. We suggest that these biochemical and morphological irregularities are related and are due to a failure of spermatogenesis, more specifically, to a higher retention of cytoplasm, which in normal sperm development is lost to the Sertoli cells as residual bodies. Thus higher CK activity and larger or irregular head size in human sperm signify cellular immaturity and a failure to complete spermatogenesis.

Fertility prognosis for infertile couples

OBJECTIVE

To develop a fertility prognosis model for infertile couples.

DESIGN

Prospective follow-up study.

PARTICIPANTS

In the period November 30, 1977 to June 1, 1985, 321 consecutive couples were investigated for infertility at Hvidovre University Hospital. Investigation of the female included detection of ovarian, cervical, and anatomic disorders, whereas in the male semen analysis and sperm penetration test (P-test) were performed. Altogether, 108 couples (34%) conceived, whereas 213 (66%) were observed for an average of 2.3 years without having achieved pregnancy.

MAIN OUTCOME MEASURE

The Cox regression model was used to predict the time required to conceive based on informations provided by fertility investigations.

RESULTS

Three of 16 prognostic variables (the period of infertility, the female infertility factor, and the P-test) possess significant prognostic information. The period of infertility and the P-test are best scored as continuous variables, whereas the female infertility factor are best categorized in four classes, i.e., normal, ovulation or cervical disorder, anatomic disorder, or a combination of disorders.

CONCLUSIONS

The three prognostic variables are combined to form a prognostic index that predicts the fecundability of the individual infertile couple.

The sperm penetration test (P-test) can predict fecundability in the male partner from infertile couples

Three hundred and twenty-one consecutive couples were investigated for infertility at Hvidovre University Hospital in the period from November 1977 to June 1985. The male partners were evaluated in two ways: the classical semen analysis, and the ability of sperm to penetrate fresh hen egg white, the P-test. A Cox regression analysis was used to describe the relation between these variables and fecundability, i.e. the time required to conceive. Four of thirteen variables--the number of morphologically normal spermatozoa, the number of motile spermatozoa, the P-test, and the man's age--each have significant relation to the fecundability. However, when covariation is considered, only the P-test and the man's age possess significant prognostic information, whereas the variables of the classical semen analysis do not. This indicates that the P-test may replace the classical semen analysis when trying to predict individual pregnancy probabilities. Finally, the P-test and the man's age are combined to form a prognostic index which predicts the fecundability of the male partner in the individual infertile couple.